Purpose :
To optimize the perceptibility of Haidinger’s brushes and to investigate its association with visual acuity and macular pigment optical density.

Methods :
This monocenter prospective cross sectional study included 92 eyes of 46 healthy subjects and 198 eyes of 99 subjects with retinal diseases affecting the macula. Each subject underwent best corrected visual acuity (BCVA) testing, funduscopy, and assessment of macular pigment optical density (MPOD) using the two-wavelength fundus autofluorescence method. Haidinger’s brushes visibility was tested with an optimized rotating linear polarizer and a controllable 3-LED color panel as light source. A simple model of macular pigment absorption was used to predict visibility of the entoptic phenomenon as a function of stimulus wavelength and MPOD.

Results :
All healthy subjects and 34% of the subjects with macular diseases perceived Haidinger brushes with the optimized setup (“blue” LED-color, 464nm). The degree of psychophysical perception and the dependency on different wavelengths was in accordance with the absorptance model. In eyes of subjects with age-related macular degeneration (n=40) and cone/cone-rod dystrophy (n=106), minimum thresholds of MPOD and BCVA (≤ 0.6 LogMAR) were identified to be generally required for the perception of Haidinger’s brushes. Subjects with macular telangiectasia (MacTel) type 2 (n=52) showed lowest values of MPOD and were consistently unable to perceive the entoptic phenomenon despite relatively preserved BCVA.

Conclusions :
Macular pigment and a relatively preserved foveal function are necessary for the perception of Haidinger’s brushes. Using an optimized setup, healthy subjects are consistently able to perceive Haidinger’s brushes. However, they cannot be seen by subjects with macular disease resulting in low BCVA or MPOD. Haidinger’s brushes are usually not perceived by subjects with MacTel type 2, likely due to their characteristic foveal depletion of macular pigment.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.